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arXiv · 2402.18802

Narrowband telecom band polarization-entangled photon source by superposed monolithic cavities

Ming-Yuan Gao·Yin-Hai Li·Yan Li·Zhenghe Zhou·Guang-Can Guo·Zhi-Yuan Zhou·Bao-Sen Shi
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Abstract

A high-quality narrowband polarization-entangled source in the telecom band is preferred to avoid frequency dispersion for long-distance transmission in optical fibers and to efficiently couple with telecom band quantum memories. Here, we report narrowband, telecom-band, polarization-entangled photon pair generation based on the superposition of single-longitudinal-mode photon pairs from two monolithic nonlinear crystal cavities in a passively stable interferometer based on beam displacers. The photon pairs generated from the cavities exhibit a high coincidence to accidental coincidence ratio of 20000 and a bandwidth below 500 MHz. Two-photon polarization interference, Bell-inequality, and quantum state tomography are performed to indicate the high quality of the entangled source. The current configuration demonstrates greater stability than traditional free space cavity-enhanced polarization-entangled state generation, which is promising for quantum communication applications.

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Ming-Yuan Gao, Yin-Hai Li, Yan Li, Zhenghe Zhou, Guang-Can Guo, Zhi-Yuan Zhou, Bao-Sen Shi. 2024-02-29. Narrowband telecom band polarization-entangled photon source by superposed monolithic cavities. https://arxiv.org/abs/2402.18802

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